Strap support barrier

ABSTRACT

A strap support barrier for an electrical cabinet, with the electrical cabinet including vertical and horizontal bus bars. The strap support barrier includes a planar member. A mounting portion coupled to the planar member. A pair of spacing portions coupled to the planar member, wherein the planar member, mounting portion and spacing portion are configured to provide electrical clearances for the bus bars. The strap support barrier can also include orifices defined on the planar member to facilitate mounting of a strap to at least one vertical bus bar. Another embodiment of the strap support barrier includes at least one guide pin coupled to the planar member and configured to align the straps with the vertical bus bar.

BACKGROUND OF THE INVENTION

The present invention relates generally to the field of electricalswitchboards and panel boards and more particularly to a device thatfacilitates spacing, alignment, and mounting of electrical equipment inswitchboard and panel board cabinets.

Distribution panel assemblies such as switchboards and panel boards aregeneral terms which cover metal enclosures, housing switching andinterrupting devices such as fuses, circuit breakers, associatedcontrols, instrumentation and metering devices. Such assembliestypically include associated supporting structures, interconnections andbus bars used for the distribution of electrical power. Voltage inswitchboards operate at voltages up to 600 volts and with continuouscurrents up to 5000 amps or higher. Such devices are also designed towithstand short circuit currents ranging up to 200,000 amps (3 phase rmssymmetrical).

Typical distribution panel equipment is composed of a lineup of severalmetal enclosures (hereinafter referred to as sections). Each section mayhave several circuit breakers stacked one above the other vertically inthe front of the section. Each section has a vertical or sectional buswhich supplies current to the breakers within the section via shorthorizontal branch busses or straps. The vertical bus bars in eachsection are supplied with current by a horizontal main bus bar that runsthrough the lineup of sections. A typical arrangement includes bus barsfor each electrical phase of a multi-phase system which may includethree power phases and a neutral.

The bus straps typically are directly attached to the vertical bussections. If the straps are large, they may require additional support.Standards organizations and other electrical codes require that minimumover-surface and through-air clearances (hereinafter referred to as“electrical clearance”) be maintained between the straps and all otherconductive components in a switchgear assembly. In a typicalconfiguration, the circuit breakers that attach to the bus straps maywholly rely on the bus strap for the circuit breaker mounting locationand support or may require an additional device or structure forattaching to the mounting rails of the cabinet.

Thus there is a need for a strap support barrier for an electricalcabinet that provides spacing, alignment and mounting of electricalequipment, such as circuit breakers. There is also a need for anapparatus that will provide support for circuit breakers and provide anisolation of connecting bus straps from each other to comply withelectric clearance requirements.

SUMMARY OF THE INVENTION

There is provided a strap support barrier for an electrical cabinet,with the electrical cabinet including vertical and horizontal bus bars.The strap support barrier includes a planar member. A mounting portioncoupled to the planar member. A pair of spacing portions coupled to theplanar member, wherein the planar member, mounting portion and spacingportion are configured to provide electrical clearances for the busbars. The strap support barrier can also include orifices defined on theplanar member to facilitate mounting of a strap to at least one verticalbus bar. Another embodiment of the strap support barrier includes atleast one guide pin coupled to the planar member and configured to alignthe straps with the vertical bus bar.

There is also provided an electrical cabinet for electrical equipment.The electrical cabinet includes a housing including at least one pair ofmounting rails mounted in the housing. At least one vertical bus barmounted in the housing and a strap support barrier coupled to themounting rails. The strap support barrier comprises a planar member, amounting portion coupled to the planar member, and a pair of spacingportions coupled to the planar member. The planar member, mountingportion and spacing portion are configured to provide electricalclearances for the bus bars.

There is also provided an electrical equipment mounting kit for use inan electrical cabinet. The electrical cabinet includes a plurality ofvertical bus bars and at least two mounting rails. The electricalequipment mounting kit includes a planar member configured to couple tothe mounting rails with the planar member defining an orifice alignedwith each vertical bus bar. A spacing portion is coupled to the planarmember separating the orifices. A bus strap is configured to couple tothe vertical bus bar through one of the orifices. Wherein, the planarmember and spacing portion maintain pre-selected distances between thebus strap and the vertical bus bars. Another embodiment of the kitincludes at least one guide pin coupled to the planar member andconfigured to align the strap with the vertical bus bar. A planar memberis configured to support electrical equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial perspective view of an electrical cabinet forelectrical equipment, illustrating the housing frame members withoutexterior walls and including a strap support barrier.

FIG. 2 is a perspective view of an exemplary embodiment of a strapsupport barrier with a mounting portion, spacing portions, and planarmember integral as one piece.

FIG. 3 is a perspective view of the strap support barrier illustrated inFIG. 2 coupled to mounting rails of an electrical cabinet andillustrating disposition of horizontal bus strap bars on the strapsupport barrier.

FIG. 4 is a perspective view of an exemplary embodiment of a strapsupport barrier mounted in an electrical cabinet, with electrical busstraps mounted on the barrier and coupled to vertical bus bars and anelectrical circuit breaker aligned to mount on the barrier and coupledto the electrical bus straps.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Before describing the exemplary embodiments of a strap support barrierfor electrical equipment in a distribution panel enclosure assembly,several comments are appropriate. Switchboard assemblies and panel boardassemblies typically include vertical (section) bus bars to distributeelectrical power within the assemblies. In a short circuit condition,extreme magnetic forces are created in bus bars as a result of the shortcircuit currents up to and including 200,000 amps symmetrical rmsflowing through such bus bars. In a three phase power system (typically)as the short circuit currents flow through such bus bars, magneticforces between adjacent bus bars tend to move such bus bars laterally(perpendicular) to the current flow. Such movement of the bus bars istypically prohibited or inhibited to avoid damage in arcing withinenclosures by bus assemblies or arc barriers and equipment arrangementswithin the cabinet.

Referring now to the figures, FIG. 1 is an illustration of an exemplaryembodiment of a panelboard 10, without the outer panels for claritypurposes and without circuit breakers, or control apparatus. However,FIG. 1 does include a base assembly of circuit breaker type electricalequipment coupled to frame members 12 of the cabinet 10 by a mountingplate system 30. FIG. 1 specifically depicts a multi-phase assemblyconventionally having power phases A B and C. A neutral bus or groundingbus can also be provided. Vertical bus bars 14 extend typicallythroughout the height of the panelboard assembly 10 for the distributionof power within the system. The equipment can be accessed from the frontside 13 of the cabinet 10.

Referring now to FIG. 2, the strap support barrier 30 includes a planarmember 32 with a mounting portion 34 coupled to the planar member 32. Apair of spacing portions 36 is coupled to the planar member 32 with theplanar member 32, mounting portion 34 and spacing portion 36 configuredto provide electrical clearances for the bus bars.

As illustrated in FIG. 3, the strap support barrier 30 is coupled to themounting rails 12 of the electrical cabinet 10 (See FIG. 1). The strapsupport barrier 30 has mounting holes 44 which facilitate mounting ofthe barrier 30 to the mounting rails 11.

Strap support barrier 30 includes orifices 45 defined on the planarmember 32 to facilitate mounting of a bus strap 40 to at least onevertical bus bar 14. The orifices 45 can be of any suitableconfiguration but typically are large enough to accommodate installationof the bus straps 40 as illustrated in FIG. 3. The location of theorifices 45 correspond to the spacings of the vertical bus bars 14 for agiven switchgear cabinet configuration. Guide pins 50 are provided toassist in positioning and locating the bus straps on and affixing themto the barrier 30. Additional electrical clearances and barriers areprovided by the spacing portions 36 which can be configured with ribbing38 (FIG. 2) to comply with spacing requirements.

The guide pins 50 function to locate and latch the bus straps 40. Theguide pins 50 enable a quick, efficient construction of a sub-assembly,comprised of the strap support barrier 30 and bus straps 40. Suchsub-assembly can be shipped as a single entity for easy userinstallation, retrofits, or upgrades in the field. It should beunderstood that other guiding configurations are contemplated, forexample, stakes with a hook feature, pegs, spaced apart ridges orsimilar structures.

The planar member 32, mounting portion 34, and spacing portions 36 canbe composed of any suitable material that is non-metallic andnon-conductive electrically. The mounting portion 34 and spacing portion36 can be integral with the planar member 32 as a single piece.

To mount electrical equipment 20 such as a circuit breaker (See FIG. 4)an electrical equipment mounting kit 60 can be used in an electricalcabinet 10. The electrical equipment mounting kit 60 includes a planarmember 32 configured to couple to the mounting rails 11, with the planarmember 32 defining an orifice 45 aligned with each vertical bus bar 14.A spacing portion 36 is coupled to the planar member 32 separating theorifices 45. A bus strap 40 is configured to couple to a vertical busbar 14 through one of the orifices 45. The planar member 32, spacingportions 32 and guide pins 50 maintain a pre-selected distance betweenthe bus strap 40 and the vertical bus bars 14.

The bus straps 40 are configured to couple directly to the electricalequipment, such as a circuit breaker 20 with the circuit breaker mountedto mounting holes 44 provided in the strap support barrier 30 withfasteners 46 (See FIG. 4). Guide pins 50 are provided on the barrier 30to position the bus straps 40. The bus straps 40 and the strap supportbarrier 30 that make up the electrical equipment mounting kit 60 areconfigured for each sized electrical equipment 20 so that additionalmounting hardware will not be necessary to secure and support theelectrical equipment 20 being mounted in the electrical cabinet 10.

Thus, there is provided a strap support barrier for an electricalequipment that provides guidance, securement, and phase isolation in asingle device for mounting electrical equipment in the switchgearcabinet. The foregoing description of embodiments have been presentedfor purposes of illustration and description. It is not intended to beexhaustive nor to be limited to the precise forms disclosed, andmodifications and variations are possible in light of the aboveteachings and may be acquired by practice of the invention. Theembodiments are chosen and described in order to explain the principlesand practical application to enable one skilled in the art to utilizethe strap support barrier in various embodiments and with variousmodifications that are suited to the particular use contemplated. It isintended that the scope of the strap support barrier be defined by theclaims appended hereto and their equivalents.

1. A strap support barrier for an electrical cabinet, with theelectrical cabinet including vertical and horizontal bus bars, the strapsupport barrier comprising: a planar member; a mounting portion coupledto the planar member; and a pair of spacing portions coupled to theplanar member, wherein the planar member, mounting portion, and spacingportion are configured to provide electrical clearances for the busbars.
 2. The strap support barrier of claim 1, wherein the mountingportion and spacing portion are integral with the planar member as asingle piece.
 3. The strap support barrier of claim 1, includingorifices defined on the planar member to facilitate mounting of a strapto at least one vertical bus bar.
 4. The strap support barrier of claim3, including at least one guide pin coupled to the planar member andconfigured to align and secure the straps with the vertical bus bar. 5.The strap support barrier of claim 1, wherein the planar member isconfigured to support electrical equipment.
 6. The strap support barrierof claim 1, wherein the planar member, mounting portion and spacingportions are non-metallic and non-conductive.
 7. An electrical cabinetfor electrical equipment comprising: a housing; at least one pair ofmounting rails mounted in the housing; at least one vertical bus barmounted in the housing; and a strap support barrier coupled to themounting rails, the strap support barrier comprising: a planar member; amounting portion coupled to the planar member; and a pair of spacingportions coupled to the planar member, wherein the planar member,mounting portion, and spacing portion are configured to provideelectrical clearances for the bus bars.
 8. The electrical cabinet ofclaim 7, wherein the mounting portion and spacing portion are integralwith the planar member as a single piece.
 9. The electrical cabinet ofclaim 7, including orifices defined on the planar member to facilitatemounting of a strap to at least one vertical bus bar.
 10. The electricalcabinet of claim 9, including at least one guide pin coupled to theplanar member and configured to align and secure the straps with thevertical bus bar.
 11. The electrical cabinet of claim 7, wherein theplanar member is configured to support electrical equipment.
 12. Theelectrical cabinet of claim 7, wherein the electrical cabinet isconfigured as one of a panelboard and a switchboard.
 13. The electricalcabinet of claim 7, wherein the planar member, mounting portion andspacing portion are non-metallic and non-conductive.
 14. An electricalequipment mounting kit for use in an electric cabinet, the cabinetincluding a plurality of vertical bus bars and at least two mountingrails, the mounting kit comprising: a planar member configured to coupleto the mounting rails, with the planar member defining an orificealigned with each vertical bus bar, a spacing portion coupled to theplanar member separating the orifices, and a bus strap configured tocouple to a vertical bus bar through one of the orifices, wherein theplanar member and spacing portion maintain pre-selected distancesbetween the bus strap and vertical bus bars.
 15. The kit of claim 1,wherein the spacing portion is integral with the planar member as asingle piece.
 16. The kit of claim 14, including at least one guide pincoupled to the planar member and configured to align and secure thestrap with the vertical bus bar.
 17. The kit of claim 14, wherein theplanar member is configured to support electrical equipment.
 18. The kitof claim 14, wherein the planar member, mounting portion and spacingportion are non-metallic and non-conductive.